Aerosol dispensing container with reserve propellant chambers

ABSTRACT

An aerosol dispensing container of the gas-propelled type which includes a plurality of reserve chambers for the propellant gas which are adapted to sequentially release their contained reserve gas supply as the pressure of the propellant gas in the main chamber drops below a predetermined level.

United States Patent May 11,1971

Appl. No. Filed Patented AEROSOL DISPENSING CONTAINER WITH RESERVEPROPELLANT CHAMBERS [56] References Cited UNITED STATES PATENTS1,959,815 5/1934 Corcoran 222/52 3,258,163 6/1966 Brush 222/52 PrimaryExaminerSamuel F. Coleman Attorney-Philip G. Kiely 6claims4nrawing FigsABSTRACT: An aerosol dis ensing container of the gas P US. Cl 222/52,propelled type which includes a plurality of reserve chambers 222/399for the propellant gas which are adapted to sequentially Int. Cl 867d5/08 release their contained reserve gas supply as the pressure of Fieldof Search ZZZ/6,52, the propellant gas in the main chamber drops below a61 399 predetermined level.

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IIIIIIl/I [III/IIIIII/j/III IIIIl/l 1 AEROSOL DISPENSING CONTAINER WITIIRESERVE PROPELLANT CHAMBERS BACKGROUND OF THE INVENTION the liquidproduct to be dispersed, e.g., hair treating liquids, j

deodorants, perfumes, food products and the like, and a gas propellantsuch as nitrogen, freon, carbon dioxide, and the like. The product andthe propellant are introduced into the can separately, and the repeatedopening of the nozzle on the can permits a portion of the product to beexpelled with a portion of the escaping propellant.

However, aerosol cans often lose propellant in a disproportionaterelationship tothe emission of product, with the ultimate result thatthe can may have a significant quantity of product but insufficientpropellant pressure to expel the remaining product.

The existence of the remaining product is readily apparent to thepurchaser, who need only shake the can to discover that, although thecan is not empty, no more productlcan be obtained therefrom. Asignificant marketing disadvantage results in that the customer feelsthat he has not received value.

A novel aerosol dispensing product has now been found which is notsusceptible to the deficiencies of the prior art.

SUMMARY OF THE INVENTION A novel aerosol container has now been foundwhich pro- I vides for a self-contained reserve supply of propellantwhich is available to dispense the product from the can when the initialsupply of propellant is depleted. The novel container comprises'a mainchamber, containing the product to be dispensed and an initial charge ofpropellant, and at least a first and second reserve chamber containingpropellant adapted to be sequentially released when the propellantpressure in the main chamber drops below a predetermined level. Anynumber of reserve chambers may be employed, but, in a preferredembodiment, the container is constructed to include three reservechambers.

The feature of the present invention also permits the employment ofpressurized containers of a size heretofore unobtainable since the priorart design of cans which mixes all the propellant with the product wouldnot permit the introduction of the quantity of propellant necessary toexpel the relatively large quantity of product.

BRIEF DESCRIPTION OF THE DRAWING I DETAILED DESCRIPTION OF THE INVENTIONThe novel pressure dispensing container of the present invention iscomposed of a main compartment for the product to be dispensed and apropellant gas and a plurality of chambers or compartments for holding areserve quantity of propellant gas. Thus, in operation the main chamberis charged in thefconventional manner with the product to be dispensedand the propellant gas to expel said product from the container. Thequantity of propellant employed in the main chamber may be varied; thequantity conventionally employed may be charged to the main compartmentor, preferably, a quantity less than that normally required for theexpulsion of the total quantity of the product. In any event, sufficientpropellant should be charged to the main compartment to provide for theemission from the container of at least a major portion of the productin the form desired, i.e., spray, foam or solid stream.

The container also contains a plurality of secondary or reserve chamberswhich are charged with propellant under pressure and which are adaptedto deliver the contained propellant to the main compartment when thepropellant pressure in the main compartment reaches a predeterminedlevel. The reserve containers deliver the contained propellant insequence; thus, the propellant level can be permitted to fall to theabove-mentioned predetermined level several times, i.e., to a numbercorresponding to the number of reserve compartments in the container.

As the product is dispersed from the container, the propellant pressurein the main chamber will fall; when a predetermined pressure level isreached, suitable valving means will open, discharging the contents ofone of the reserve chambers into the main compartment thus providingsufficient propellant to insure the continued proper emission of theproduct from the can. With repeated use, the pressure in the can againfalls to a predetermined level, which may be the same or different fromthe first-mentioned predetermined pressure; a second reserve'chamberreleases its stored propellant into the main chamber, again raising thepropellant level in the main chamber to a satisfactory level forefficient operation. As the product is continued to be expelled from thecan, the pressure may again drop to a predetermined level, which may bethe same as either or both of the above predetermined levels, or a stilldifferent pressure level. The contents of a third reserve chamber willdischarge its contained propellant into the main compartment.

By employing the novel container of the present invention,

various combinations of pressurized levels of propellant may beemployed. For example, it may be desirable to employ the same quantityof propellant that would be required to eject the propellant equallyamong the main and reserve chambers. Thus, thevariation in productexpulsion force would vary only slightly throughout the use life of thecontainer. A uniform average pressure would always be available to expelthe contents of the cans. .Itis preferred, however, that a relativelylarge percentage of the total propellant be employed in the maincompartment, e.g., approximately percent of the total propellant withthe reserve compartments functioning as true reserve compartments toprovide for a more efficient level of propellant in the main chamber ofthe container upon extended use of the container and to ensure that thelast residual quantity of product is effectively discharged from thecontainer in the form, i.e., spray, foam, etc., originally intended bythe designer of the product and container.

Deficiencies in manufacture of the container or valve, corrosion, orvalve malfunction resulting from accumulation of product therein maycause leakages resulting in a slow loss of propellant upon storage. As aresult, the level of propellant may drop to a level inadequate todischarge the product, leaving a container with a relatively largequantity of product but no methodof removing it from the container. Withthe container of the present invention, however, leakages would notrequire discarding the container because loss of the propellant wouldonly be from the main compartment, and when the loss has reached a pointwhere the first reserve chamber would be activated, a new supply ofpropellant would be provided to the main chamber. It would not be likelythat all the propellant would be discharged to the main chamber from thereserve chambers, since such a situation would probably result from aserious leak, which would be obvious from visual inspection of the canand require discarding the can as a safety measure. By virtue of thepresent invention, however, most containers which would ordinarily bediscarded as a result of leakage of propellant, would remain useable.

Still a further advantage obtained with the container of the presentinvention resides in the ability to employ containers of a-sizeheretofore not useable. In the past, an effective limit has been placedon the size of the container that can be used; the amount of propellantnecessary to expel a relatively large quantity of product from acontainer would be excessive. The

relatively high pressure would drive the contents out at an unacceptablevelocity during initial use, while repeated use would result in greatvariations in discharge pressures. The

high pressures produced by large quantitiesof propellant would alsorender the valves highly susceptible to leakage.

Employing a container of the present invention, however, pressurizedcontainers of a size heretofore not obtainable can be achieved. Bypressurizing the main chamber with only suffi' cient propellant to expelthe product at the desired velocity and form, a series of reservechambers can be employed to maintain a predetermined uniform propellantrange over the entire use period of the container sufficient to provideproduct at the desired pressure, but not with an excessive quantity ofpressure which may produce the above-mentioned detrimental results.

Turning now to the drawings, FIG. I shows container I with valve 13 andspout 14 through which the product passes. Valve 13 and spout I4 are notof any specifically required construction; their selection is determinedby the type of product to be used in the container and suitable valvesand spouts are known to the art. Container is composed of maincompartment 11, wherein propellant and product 12 to be expelled arecontained. The container also includes a plurality of reserve chambers15, I6 and 17. While three are shown, it should be understood that anynumber can be employed depending upon the particular set of conditionsdesired in the container. As shown in FIG. 1, the reserve chambers l5,l6 and 17 are charged with propellant at the same time as compartment11. As the propellant reaches a preselected level in compartment 11,check valve 18 will open admitting propellant into tube 19 from which itpasses into the reserve chambers through apertures 20, 21 and 22,respectively. As the propellant in compartment 11 is depleted throughuse, the pressure will drop. Reserve chamber has valve 15a communicatingwith compartment 11' and which is adapted to open responsive to theaforementioned pressure differential between compartment 11 and chamber15 discharging the propellant from-chamber 15 into compartment 11, thusmaking additional propellant available for the efficient emission ofproduct 12 from the container.

Upon repeated use of the container the propellant level will again dropto a predetermined level which will activate valve 16a releasing thepropellant in chamber 16 into compartment 11. As mentioned above, thepressure level which will activate valve 160 may be the same ordifferent from that which will activate valve 15a or any of the othervalves.

As the propellant level in the main compartment is depleted, apredetermined pressure level is again reached which activates valve 17adischarging the propellant from chamber 17 into compartment ll.

As shown in FIG. 1, the contents from the reserve chambers pass througheach of the preceding chambers and into compartment II. It should beunderstood that the reserve chambers may also discharge directly intothe main compartment without passing through any other chambers.

The valves employed in the reserve chamber may comprise any type ofvalve actuated by a pressure differential; for exam ple, a hinged,spring-loaded valve, shown in an open position in dotted lines inFIG. 1. In an alternative embodiment, a membrane or diaphragm of asynthetic polymeric material or metal adapted to rupture at a givenpressure differential may be employed.

' spout l4, reserve chambers 25, 26 and 27. The pressure responsivevalves 25a, 26a and 27a are polymeric membranes which'rupture when apredetermined pressure differential is attained between the reservechamber and the next adjacent chamber communicating with compartment 11.In the embodiment shown in FIG. 2 charging the reserve chamber isaccomplished by introducing the propellant to compartment 11, a portionof which passes through check valves 30, 31 and 32 which are selected too n at a iven pressure so that the pressure in compartment 1 will eabove that in the reserve chambers during filling to avoid prematurerupture of the membranes.

FIG. 4 illustrates still another embodiment of the present inventionwherein container 10, composed of main compartment 11, valve 13, andreserve chambers 35, 36 and 37 are charged with propellants in twooperations. Compartment 1] is first chargedwith product and propellantin a conventional fashion. A dip stick 39 is then inserted through valve13 in a gastight manner and inserted into check valve 40 in the bottomof compartment 11. Check valve 40 is connected to tube 41 whichcommunicates with chambers 35, 36 and 37 through apertures 42, 43 and44. A pressurized source of propellant is connected to the opposite endof tube 39 and propellant is passed through said tubes and check valvesinto the reserve chambers. To avoid leakage from one reserve chamber toanother, suitable valve means should be inserted in line 41. In stillanother alternative, check valves are located at apertures 42, 43 and 44without any valve on the bottom of compartment II.

For simplicity of illustration, the drawings are shown without any diptube. It should be understood, however, that as the product requires,dip tubes may be employed.

The novel containers of the present invention are suitable for use withsubstantially any product employed in pressurized containers. Similarly,any suitable propellant known to the art may be employed, such asnitrogen, freon, carbon dioxide, and the like.

lclaim:

I. An expendable dispensing container comprising a main compartment forthe substance to be dispensed and a gas propellant for ejecting saidsubstance from said container, and at least a first and second reservechamber containing gas propellant, said reserve chambers adapted tosequentially release substantially the entire contents thereof into saidmain compartment.

2. A product as defined in claim I wherein said reserve chambers includea spring-loaded valve adapted to open and to release substantially theentire contents thereof when the pressure in the next adjacentcompartment drops to a predetermined level.

3. A product as defined in claim 1 wherein said reserve chambers includea diaphragm adapted to rupture at a predetermined pressure differential.

4. A product as defined in claim I wherein said container includes threereserve chambers.

5. A product as defined in claim 1 wherein said propellant comprisesfreon. t

6. A product as defined in claim 1 wherein said reserve chambers includecheck valves whereby said reserve chambers are charged with propellantthrough said check valves.

2. A product as defined in claim 1 wherein said reserve chambers includea spring-loaded valve adapted to open and to release substantially theentire contents thereof when the pressure in the next adjacentcompartment drops to a predetermined level.
 3. A product as defined inclaim 1 wherein said reserve chambers include a diaphragm adapted torupture at a predetermined pressure differential.
 4. A product asdefined in claim 1 wherein said container includes three reservechambers.
 5. A product as defined in claim 1 wherein said propellantcomprises freon.
 6. A product as defined in claim 1 wherein said reservechambers include check valves whereby said reserve chambers are chargedwith propellant through said check valves.